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GT Grade carbon custom build long-term review

Warren tries out Shimano’s gravel specific GRX Di2 group on what's fast becoming one of his favourite new gravel bikes

Our rating 
4.5 out of 5 star rating 4.5
GBP £2,700.00 RRP
Approx – custom build
Custom built GT carbon gravel bike

Our review

This is a long-term review and the score may change as I spend more time on the bike
Pros: Light and versatile gravel bike with a smooth ride
Cons: The dry conditions tyres aren’t great in any other circumstances
Skip to view product specifications

This Grade isn’t one you can buy off the shelf. The frameset is the same as the GT Grade Carbon Expert (£1,999.99), but while that comes with Shimano 105, mine has been built up for me by Shimano using its gravel-specific GRX 810 Di2 groupset.


Gearing-wise, I went with the wider option on the rear cassette – 11-42 with a 40t front ring to give a decent low climbing gear for when things get tough and steep.

Other options, such as the satellite shifters mounted on the top of the bars, mimic one of my favourite set-ups from SRAM’s Red eTap group. I like to have the blips mounted on the tops for shifting when up out of the saddle grinding out on a climb.

Finally, I chose Shimano’s intriguing sub-brake levers (BLRX812SET), which run inline from the Di2 shifters and offer braking from the tops, just like cross-top levers of old that were popular around a decade ago.

This choice did however mean that due to the real estate on my PRO Discover bar setup I couldn’t fit a standard Garmin out-front mount, so I was looking at something like the F3 Form mount, which attaches via the stem bolts.

These are the best part of £50, though, so a bit of Google searching later I found an alternative on eBay for £14.99 – complete with all the fittings for both a Garmin and a light (using a Go-Pro mount) – which keeps it out front and in-line with the stem, a really neat solution.

Pro Discover handlebar
I chose a different setup to the norm on this bike with sub-brake levers.
Russell Burton

The drivetrain is fitted with Shimano’s WU111 Bluetooth antenna, which allows the Di2 to sync with my Garmin Edge 1000, the new 815 shifter and its hidden button on the side of the hood. I’ve assigned that hidden button to operate screen switching on the Garmin head unit, so I don’t need to move my hands from the bars – even more important when riding on gravel.

Considering the amount of additional equipment I have on this bike (dropper post, extra brake levers, remote shifters, XTR pedals and two bottle cages), the 9.5kg all-up weight is pretty decent.

GT Grade carbon (custom) specification

  • Weight: 9.5kg (L with Shimano XTR PD9100 pedals) 
  • Frame: GT Grade
  • Fork: GT Grade carbon
  • Chainset: Shimano GRX 810 Hollowtech II, 40t chainring
  • Chain: Shimano
  • Brakes: Shimano GRX RX810
  • Shifters: Shimano GRX ST RX815, satellite shifters, WU111 Bluetooth antenna
  • Rear mech: Shimano GRX Shadow RD+
  • Wheels: Shimano GRX Alloy 650b
  • Tyres: Vittoria Terrano Dry 47c
  • Bar: PRO Discover aluminium bar
  • Stem: PRO Discover
  • Saddle: PRO Stealth
  • Seatpost: PRO Discover dropper
  • Bottle cages: PRO carbon
  • Accessories: Stem-bolt mounting for Garmin GPS (£14.99)

GT Grade carbon (custom) geometry

  • Size: Large (58cm)
  • Head angle: 72.3 degrees
  • Seat angle: 73 degrees
  • Wheelbase: 1,070mm
  • Chainstays: 44.5cm
  • Stack: 61.2cm
  • Reach: 40cm

Why did I choose this bike?

I’ve always been a fan of the GT Grade, the original launched back in 2014 (as a 2015 model year bike) and was a groundbreaking machine, we even awarded it best debut in our 2015 Bike of the Year awards.

The bike is designed for adventure and to be raced at a gran fondo, but its large volume tyres and disc brakes mean it can still get off the beaten track to ride dirt roads and gravel.

GT says the bike is aimed at the competitive sportive rider who wants to expand their horizons and ride way beyond tarmac.

The new bike is much like the original, it just gets more tyre clearance and can be used with both 650b and 700c wheels. The back-end has been designed to allow much more compliance and comfort than the original, too, oh and the geometry is now a bit more aggressive.

GT Grade initial setup

I was always going to go GRX on the Grade because the bike has already been built up by Shimano as part of its GRX launch, which I attended.

I have to admit to being a little skeptical initially about GRX; it seemed less like a new groupset launch and more like a collection of parts from existing mountain bike and road products. However, I’m more than happy to report back that that’s simply not the case.

On building it up and running through the options list, a few choices needed to be made. I opted for 1x – up until then I’d only ridden a 2x Grade – and I also opted for 650b GRX wheels because I’ve not tried them out on the Grade yet.

GT Grade first impressions

GRX has proven itself totally reliable, and I’m suitably impressed, but the best part by far is the GRX 810 STI lever, which is a marvel. The hood shape, lever shape and lever actuation are all unique to the Di2 model, with other models having a much more traditional lever design.

The hood is one of the most comfortable I’ve used on any group, but then I’ve never really had an issue with many and having big hands I even found the old lumpy BR-405 lever reasonably good to hold.

The lever action introduces Shimano’s Servo Wave tech for the first time on a road bike, normally found on mountain bike operations, and it is simply brilliant.

Servo Wave is more about brake action than anything else. The initial lever travel is fast, so little movement is required to get that initial contact and then the power ramps up rapidly through the lever stroke for some of the best feeling braking I’ve tried from the hoods.

I’m more than comfortable staying up on the hoods and single-finger braking on the trails, and even on some fast, rocky and truly twisty mountain bike trails on a recent trip to Montana, riding the awesome Whitefish Bike Retreat trails. On any other brake lever shape I would have been down in the drops.

As I say, with bigger hands, I don’t have a problem braking from the hoods using standard levers, but it’s a known issue for smaller handed riders.

PRO Stealth saddle sitting on a PRO Discover dropper post
PRO’s Stealth saddle on its Discover dropper post.
Russell Burton

The final piece of the puzzle is the PRO Discover dropper post with its clever remote lever designed for drop bars.

Now, a dropper is a mountain bike invention where you can drop the seatpost down into the frame to give you more clearance to manoeuvre when riding down steep off-road slopes or when riding through technical terrain. It may seem a little superfluous on what’s ostensibly a road bike, but I’ve used it more and more, and ridden much further afield than I would have had I not had it.

The Grade is such a sorted chassis, it superbly combines really agile handling traits with a very compliant frame and it all comes in a package that’s impressively light – the Grade frame is just 980g, impressive stuff for a gravel bike.

GT Grade upgrades

The wheels are also from Shimano – 650b GRX alloy units. These are up to Shimano’s usual quality and are shod with Vittoria Terrano Dry 47c tyres.

The tyres were great in Montana’s dry, dusty conditions, but back in the UK on some damp rides they have all the grip of Bambi on ice, so I’ll be switching those for the winter. Long term I may look to upgrade the wheels to something a little lighter and also add a set of 700c wheels into the mix.


And I’ll certainly be looking at some sort of rear ‘guard for when I’m riding in the filth.

BikeRadar‘s 2020 long-term test bikes

At the start of the year, every member of the BikeRadar team selects a long-term test bike to ride over the course of the following 12 months. Some choose a bike from their favoured discipline and ride it hard for a year, others opt for a bike that takes them outside of their comfort zone.

Our long-term test gives us the opportunity to truly get to grips with these machines, so we can tell you how they perform through different seasons and on ever-changing terrain.

We also use them as test beds for the latest kit, chopping and changing parts to see what really makes the difference – and help you decide which upgrades are worth spending your money on.

To see all of the BikeRadar team’s 2020 bikes – and stay up-to-date with the latest developments – visit our long-term review hub.

Product Specifications


Price GBP £2700.00
Weight 9.5kg (L) – L with Shimano XTR PD9100 pedals
Brand Gt


Features Bottle cages: Pro carbon
Accessories: Ebay bought stem-bolt mounting Garmin mount (£14.99)
Brakes Shimano GRX RX810
Chain Shimano
Cranks Shimano GRX 810 Hollowtech II, 40t chainring
Fork GT Grade carbon
Frame GT Grade carbon
Handlebar Pro Discover aluminium bar
Rear derailleur Shimano GRX Shadow RD+
Saddle Pro Stealth
Seatpost Pro Discover dropper
Shifter Shimano GRX ST RX815, satellite shifters, WU111 Bluetooth antenna
Stem Pro Discover
Tyres Vittoria Terrano Dry 47c
Wheels Shimano GRX Alloy 650b